Sunday, September 4, 2011

JTWC Prognostic Reasoning for Tropical Cyclone Advisory 06 - Tropical Storm Noru

WDPN31 PGTW 041500
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W WARNING NR 06//
RMKS/
1. FOR METEOROLOGISTS.
2. 12 HOUR SUMMARY AND ANALYSIS.
A. TROPICAL STORM (TS) 16W (NORU), LOCATED APPROXIMATELY 600 NM
NORTHEAST OF IWO TO, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 16
KNOTS OVER
THE PAST SIX HOURS. ANIMATED INFRARED (IR) SATELLITE IMAGERY
SHOWS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH
THE MAJORITY OF THE CONVECTIVE BANDING WRAPPING AROUND THE EASTERN
TO NORTHERN PERIPHERY. A 041018Z SSMIS DEPICTS AN ELONGATED AND
WEAKENING LLCC. A 031033Z ASCAT PASS ALSO DEPICTS THE ELONGATED LLCC
WITH AN EXPANSIVE AREA OF STRONG STORM FORCE WINDS ALONG THE EASTERN
AND NORTHERN PERIPHERIES. THE INITIAL POSITION IS BASED ON THE IR
AND SSMIS IMAGERY WITH LOW CONFIDENCE. UPPER LEVEL ANALYSIS
INDICATES A TROPICAL UPPER TROPOSPHERIC TROUGH IS WRAPPING AROUND
THE NORTHERN AND EASTERN SIDES OF TS 16W, BUT APPEARS TO BE FILLING
TO THE NORTH. CONSEQUENTLY, THE OUTFLOW IS LIMITED ON THESE SIDES
AND REMAINS STRONG TO THE SOUTHEAST.
3. FORECAST REASONING.
A. THERE IS NO SIGNIFICANT CHANGE TO THE FORECAST PHILOSOPHY.
B. TS 16W IS EXPECTED TO CONTINUE TRACKING GENERALLY NORTHWARD
ALONG THE WESTERN PERIPHERY OF A MID-LEVEL SUBTROPICAL STEERING
RIDGE THROUGHOUT THE FORECAST PERIOD. TS NORU SHOULD SLOWLY
INTENSIFY DUE TO IMPROVED OUTFLOW INTO A MID-LATITUDE TROUGH TO THE
NORTHWEST AND WARM SEA SURFACE TEMPERATURES (SST) (>26 DEGREES
CELSIUS) UNTIL AFTER TAU 24 WHEN THE SSTS DECREASE. VERTICAL WIND
SHEAR ASSOCIATED WITH THE MID-LATITUDE TROUGH SHOULD INCREASE AND
AID IN WEAKENING THE SYSTEM. TS 16W IS FORECAST TO BECOME AN EXTRA-
TROPICAL LOW BY TAU 48. NUMERICAL MODEL GUIDANCE IS IN GOOD
AGREEMENT WITH THE NORTHWARD TRACK AND THIS FORECAST IS IN GOOD
AGREEMENT WITH MODEL CONSENSUS.//
NNNN

No comments:

Post a Comment